Instrument for delivering substances into the anatomy

Abstract

A medical instrument that includes a needle and an expandable member located at a distal end of the needle. The expandable member includes a blocking member. The expandable member is configured to move tissue away from a distal end of the needle and/or from a distal end of a tubular member that is in fluid communication with a substance source. A substance is configured to be expelled into the anatomy through the expandable member. The blocking member is configured to restrict or prevent the substance from being expelled through the portion of the expandable member that includes the blocking member.

The invention claimed is: 
     
       1. A medical instrument comprising:
 a substance delivery apparatus including:
 a needle; 
 an expandable member enabled to extend distally beyond a distal end of the needle, the expandable member supporting a plurality of fingers that extend from a proximal end of the expandable member to a distal end of the expandable member, the plurality of fingers being further configured to expand in response to the expandable member being moved in a distal direction beyond the distal end of the needle and configured to collapse in response to the expandable member being moved in a proximal direction into the needle; 
 a tubular member in fluid communication with a substance source and having a distal end fluidly coupled to the proximal end of the expandable member and configured to deliver a substance from the substance source through the proximal end of the expandable member; 
 a first blocking member that covers a portion of the expandable member and that defines at least one opening configured to deliver the substance, the blocking member being configured to permit the substance passing through the proximal end of the expandable member to be delivered through the opening and to flow without interference out of the substance delivery apparatus in the distal direction and to prevent the substance from flowing past the expandable member in the proximal direction; and 
 a second blocking member that is located distal of the blocking member, wherein the second blocking member comprises a plurality of apertures configured to allow the substance to pass therethrough. 
 
 
     
     
       2. The medical instrument according to  claim 1 , wherein the blocking member is substantially free of any apertures. 
     
     
       3. The medical instrument according to  claim 1 , wherein a length of the blocking member is substantially the same as a length of the second blocking member.